1. Field of the Invention
The present invention relates to a boom foot pin attachment and detachment apparatus installed in a construction machine.
2. Description of the Related Art
In general, in a construction machine such as a crawler crane, there is a known configuration that when a base end part of a boom, that is a boom foot is attached to an upper rotating body, a bifurcated connection portion is formed on left and right two positions on one of the upper rotating body and the boom foot, and a connection portion inserted into the above connection portion is formed similarly on left and right two positions on the other, and the boom foot is detachably connected to the upper rotating body in a state that both pin holes provided in both the connection portions are aligned. Particularly, in a large sized machine, since a boom foot pin is large and heavy, a foot pin attachment and detachment apparatus for automatically performing insertion and pull out of the foot pin is installed.
As the above apparatus, for example as disclosed in Japanese Patent Laid-Open No. 2002-226174, there is a known configuration that a base end flange is attached to an inner piece of the bifurcated connection portion by bolts, including a cylinder bracket in a substantially cylindrical shape enabling the boom foot pin to move between an insertion position where the boom foot pin is inserted into the pin holes and a pull out position where the boom foot pin is pulled out from the pin holes, and a hydraulic cylinder in which a cylinder main body thereof is attached to a surface (inner surface) of a circular body fixed to a front end of the bracket by bolts and a piston rod thereof is connected to the boom foot pin. For example as disclosed in Japanese Patent Laid-Open No. 2000-211888, the above apparatus is provided as a pair on the left and on the right, and hydraulic cylinders of left and right apparatuses come close in the vicinity of a center line of the upper rotating body.
Meanwhile, in the large sized machine, due to a problem of space on the upper rotating body side, when a plurality of winches are installed to the boom, a number of hose pipes are arranged from the front side of the upper rotating body to a drive motor of the winches on the boom side in order to move the winches. Since the pipes are required to be removed at the time of detaching the boom, the pipes are arranged by using a quick coupler and there is a need for performing connection and removal works of the pipes at the time of assembling and disassembling the boom.
However, since the connection and removal works of the pipes are performed on the front side of the upper rotating body in which the above mentioned apparatus is installed, there is a problem that the apparatus is disturbing the works and hence it is not easy to perform the works.